After lifeguard agencies in San Diego County decided to donate 16 lifeguard towers to their Baja California counterparts, simply moving the 2,500-pound structures presented a daunting challenge.

But that is turning out to be the easy part. The biggest hurdle has been getting approval from Mexican customs. Two weeks after they were set to cross the border, the structures remain locked in an Otay Mesa storage yard.

“These are key to saving lives,” said Aaron Quintanar, an Imperial Beach lifeguard who has been a link between Southern California agencies donating the towers and the Mexican lifeguards preparing to receive them in Tijuana, Rosarito Beach, Ensenada and Punta Abreojos in Baja California Sur.

Saying the proper paperwork was missing, Mexican customs authorities refused to allow the towers to cross the border May 29, the day the donors had lined up volunteers, forklifts and tractor-trailers needed to move the structures.

“The issue we're having is their size,” said Michael Kieley, a liaison officer with the Tijuana Fire Department, which is the designated Mexican recipient of the towers.

Although transporting lifeguard towers across the border presents unusual logistical and legal challenges, U.S. groups for years have struggled with sending donated items to Mexico under government rules designed to prevent contraband.

“The error people commit is assuming there is no procedure,” said Carlos Ramírez Escoto, Mexico's federal customs administrator for Tijuana. “We understand the work that these people do, but they must help us help them.”

Many nonprofit groups at the border say the process can be cumbersome. When Carlos Torres, a federal congressman from Tijuana, saw groups struggling with the complexity of cross-border donations, he began asking questions.

“Many rules that we have in Mexico are defined 3,000 kilometers away in Mexico City, and here at the border we have a far different dynamic,” Torres said in an interview.

Torres worked closely with customs officials in Mexico City to streamline the process of cross-border donations through a new procedure known as the firma electronica, or electronic signature.

The new form cuts the steps only for those U.S donors whose recipient in Mexico has been certified by the federal government to receive donations.

Pedro Cruz, director of the Fundación Castro Limón, a Tijuana organization that pays for children's cancer treatment, has much praise for the new procedure.

Donations that once might be stuck for months at the border now can cross in a matter of hours, Cruz said. But other items that require a second level of authorization by separate Mexican agencies – such as the health or agriculture ministries – still can face lengthy delays, he said.

“I'd like to see this as a first step,” Cruz said of the electronic signature.

The lifeguard towers were donated through SDALERT, a coalition of San Diego County lifeguard agencies.

They look like tiny cottages, 9 feet tall and measuring 12 feet by 12 feet. Purchased new, the fiberglass towers would cost $14,000 to $16,000 apiece. But now more than 10 years old, with their steel supports showing rust, they would normally be headed for a landfill. The disposal cost for all 16 units was estimated at $20,000, said Quintanar, the Imperial Beach lifeguard.

He said the towers “just need a little TLC.”

The rusting steel supports have been cut off, and the Mexicans will have to build their own support structures. The towers need painting and repairs, but Tijuana's lifeguards are looking forward to getting them.

“They're in really good condition for us,” said Juan Hernandez, head of aquatic rescues for the Tijuana Fire Department.

Tijuana's towers are so deteriorated and dirty that “lifeguards prefer not to climb onto them,” Hernandez said.

Concerned about the difficulty of transporting the towers across the border, Tijuana Mayor Jorge Ramos' administration now has become directly involved, meeting with customs officials and making sure the necessary paperwork is submitted.

The towers' crossing date has not yet been set, Quintanar said last week. He is sure they will be put to good use by Mexican lifeguards once they arrive: “You want your front-line people in a high, comfortable place where you can have a great view.”